In recent years, thin-client-based information processing systems have received attention and medical service has started introducing the thin-client-based systems. The thin-client-based medical system has a network such as a hospital LAN through which a single server and multiple clients (thin client terminals) are connected with each other. In the network, the thin client terminals do not contain hard disk drives and the server stores therein data and an application to cause the thin client terminals to operate. Specifically, the server stores therein data of an image took by another image processing equipment, performs image processing, and activates various application programs in response to requests from the thin client terminals. The thin client terminals have only a data displaying function and a minimum inputting function.
The thin client terminals do not store therein application programs and data, so that processing loads of the thin client terminals can be reduced and data can be centrally managed on the server. In addition, since the thin client terminals do not contain hard disk drives, the thin client terminals are inexpensive and an increased number of thin client terminals can be introduced and connected with the network.
In the thin-client-based systems, a plurality of users may access same data on the server through their own thin client terminals. Also, while a plurality of thin client terminals are concurrently accessing same data on the server, the thin client terminals may update the data. Conventionally, in such a case where a user is accessing data on the server, another user can read but cannot update the data. In addition, assume that when a plurality of users are concurrently accessing same data, one of the users tries to update this data. If another user has already updated the data, it is determined which of the modifications will be made to the original data.
However, at health care sites, for example in emergency situations, if a user cannot update data because another user is accessing the data, the data cannot be updated to latest data. Also in a situation that occurs when a plurality of users are concurrently accessing same data, where one of modifications to the data is needed to be selected, an operating mistake may delete the data, resulting in a re-examination or a misdiagnosis.